WASHINGTON -- As the White House gears up its effort to stem gun violence in the aftermath of last month's mass shooting at a Connecticut elementary school, President Obama is considering taking unilateral action to begin tackling the issue.

The White House won't say specifically what actions the president is weighing, but Vice President Biden on Wednesday made clear that the use of presidential "executive order" is very much on the table. Biden is heading a task force on gun violence that will develop a broad set of recommendations for Obama.

"The president is going to act," Biden said at the start of a task force meeting with representatives of gun safety and victims' groups. "There are executive orders; there's executive action that can be taken. We haven't decided what that is yet. But we're compiling it all with the help of the attorney general and the rest of the Cabinet members, as well as legislative action that we believe is required."

Today, Biden will hold a similar session with hunters and gun owners groups, including a representative from the National Rifle Association, and a separate meeting with entertainment industry officials. The NRA, the largest and most powerful gun rights group, declined to comment on Biden's suggestion that Obama is pondering taking executive action.

The NRA, which has said in the aftermath of last month's shooting tragedy that it opposes new gun legislation, was low-key about its expectations for the meeting with Biden. "We got an invite late Friday," spokesman Andrew Arulanandam said. "We are sending a representative to hear what they have to say."

Obama has endorsed calls from some Democratic lawmakers to reinstate an assault-weapons ban, restrict the sizes of high-capacity ammunition magazines and tighten background checks - all requiring legislative action.

But the coalition of Mayors Against Illegal Guns, led by New York Mayor Michael Bloomberg, has called for Obama to consider several measures that they said could be implemented without congressional approval:

Step up prosecution by the Justice Department of felons and others prohibited from buying weapons when they attempt to buy them. In 2009, the FBI referred 71,000 cases to the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), but U.S. attorneys prosecuted only 77.

Require federal agencies to report records to the National Instant Criminal Background Check Systems. Federal agencies are supposed to submit mental health, substance abuse and other records that prohibit a person from owning a gun, but few do, according to FBI data reviewed by the mayors group.

Appoint an ATF director. The federal agency charged with enforcing gun laws has gone without a confirmed director for six years.